I bought a Raypak heater for my new AG pool last summer, based largely on advice from ps0303 (Paul) that I read in this forum. It works great. Thanks, Paul! However, it makes a whining/whistling noise. Iím pretty sure the noise is caused by insufficient water flow (thanks again to Paulís posts). Iíd like advice on the best course of action. Here are some options Iím considering:
- Live with it. The noise is a minor annoyance. Apparently the real downside is not the noise itself, but the fact that itís a symptom of the temperature being too high inside the heater, which can accelerate scale buildup. Would this be very likely to shorten my heater's life?
- Set the filter multiport to recirculate when heating. I tried this for a few minutes, and the noise was almost eliminatedóreduced to an occasional very quiet squeak. But that would send unfiltered water through the heater. Bad idea, right?
- Optimize plumbing layout. The pool builder used 1.5Ē flexible hose, and I added a heater bypass made of 2Ē PVC. The flexible hose has some tight turns that could be improved by adding supports, and thereís a 90 degree elbow at the pump inlet that points away from the skimmer (***?) that I think should be eliminated anyway.
- Replace all 1.5Ē flexible hose with 2Ē PVC. Could this increase flow rate substantially?
- Upgrade my 1HP pump. Iíd likely go to a 1.5HP VS and run it at a much lower speed when not heating. My concern here is whether I could damage my filter. My SD40 sand filter is rated for 40gpm maximum, according to the brochure on the Pentair website. I fear that I may be caught between a rock and a hard placeÖ maybe the filter canít handle the water flow that the heater needs? Will I need to upgrade both the pump and filter to satisfy the heaterís water flow demand?
One more related question: besides low flow, the other documented cause of whistling in the Raypak heaters is a faulty unitherm governor (UG). I removed mine and tested it in a bowl of hot water and it expanded like itís supposed to. However, the UG gasket was twisted. I straightened it and lubed it, but itís still crimped and imperfect. Is there any chance that a new gasket would solve the noise problem?
Thanks in advance for any and all advice.